Case Study: Catenary Screen (Brodnica, Poland)

PROJECT – Modernization of the Central Pumping Station in Brodnica, Poland
CUSTOMER – Municipal Water Supply and Sewerage Company Ltd. in Brodnica, Poland
OBJECT – Central Pumping Station at Piaski Street in Brodnica
COMMISSIONING – January – March 2023

Modernization plans and objectives 

According to the modernization plan for the Central Pumping Station on Piaski Street in Brodnica, the purpose was to replace the existing worn-out mechanical screens with bar screens and to increase the efficiency of solids removal from incoming wastewater. The entire modernization of the facility has been divided into the following stages: 

  • Stage No. I – January 2023 – delivery and installation of the first catenary screen KR 1322 with a clearance of 8 mm for wastewater channel No. 1
  • Stage No. II – March 2023 – delivery and installation of the second catenary screen KR 1322 with 8 mm clearance for wastewater channel No. 2
  • Stage No. III – planned – delivery and installation of a screw compacting press to reduce the amount and degree of moisture of the generated debris.

Situation before modernization

The city’s wastewater flows through one main sewer, which is divided into two identical channels, each with a width of 1240 mm and a depth of 2100 mm.

Prior to the replacement of the equipment at the pumping station, there were quite frequent problems caused by the failure of already depleted mechanical screens. In addition, the solid debris collected by the screens that were dumped on the trailer contained a large amount of water.

The main problems encountered so far by the pumping station staff included:

  • problems associated with a quite high failure rate of the depleted screens
  • high costs associated with repairing and maintaining the screens in continuous operation
  • the need for constant supervision and response to problems related to the ongoing operation of the pumping station.


After discussions with the Customer and after analyzing the situation of working conditions at the pumping station on Piaski Street in Brodnica, ESMIL PRODEKO-EŁK specialists decided to select for this project two catenary mechanical screens KR 1322 with a clearance of 8 mm with an average throughput of Qavg=1300 m3/h each. 

Screens Esmil

Installation of the new equipment allowed to obtain the following results:

  • the amount of removed screenings has increased significantly due to the use of a screen with a clearance of 8 mm;
  • the special design of the chain made it possible to more effectively collect and extract from wastewater various types of pollutants flowing in it, including large amount of wipes;
  • the time required to service the screens was reduced by 90% to the necessary minimum;
  • there has been a significant decrease in the number of breakdowns and repairs at the downstream stages of wastewater treatment and sludge treatment;
  • the need to work in manual mode has been eliminated, through the use of automation of the operation mode.


The modernization of mechanical wastewater treatment at this pumping station carried out so far has made it possible to increase the efficiency of wastewater treatment of large and medium pollutants thanks to the use of catenary screens. These types of screens are equipped with a chain of special design and do not have any bearings and shafts in the part submersed in the wastewater. Thanks to such protection, further stages of wastewater treatment are also protected from the adverse effects of solids flowing in the wastewater.

In addition, MWWTP in Brodnica plans to expand the currently installed screenings collection system with a screw compacting press in the future. They plan to install it behind the screens, which would allow the press to receive debris collected by both screens, wash it, and then compact it and transport it to a trailer or container. The use of screw compacting press will make it possible in the future to reduce the volume and weight of the debris generated by up to 3 times.

The modernization of the mechanical wastewater treatment equipment at the Central Pumping Station on Piaski Street in Brodnica, which has been carried out so far, has fully met the set requirements and ensured stable and trouble-free operation of further stages of wastewater treatment.

Case Study – Dairy Processing Plant (Pennsylvania, USA)

CAPACITY OF WWTP up to 26,5 m3/day
END USER / CUSTOMER – Dairy Processing Plant (Pennsylvania, USA)

At Esmil, we excel at providing tailored solutions that address even the most unique industrial challenges. Our recent success story in Pennsylvania demonstrates our commitment to efficiency, cost savings, and environmental responsibility.

The Challenge:

A processing/industrial facility in Pennsylvania faced a daunting task – dewatering up to 26.5 m3/d of dairy sludge, starting with an initial dry solids content ranging between 3 and 3.5%. Their primary goal was to elevate the dry cake solids to above 15%, significantly reducing the expenses associated with haul out.

Our Innovative Solution:

Esmil stepped in with an approach that perfectly matched the plant’s requirements:

  • 2-Drum Multi-Disc Screw Press MDQ-202CD: With relatively light processing needs, we specified the MDQ-202CD, a compact yet high-performance dewatering solution.
  • Enclosed Shaftless Screw Conveyor: As part of our comprehensive solution, we included our enclosed shaftless screw conveyor, ensuring smooth and efficient transport of dewatered sludge.

Dehydrator MDQ

Minimizing Polymer Consumption:

Our solution not only achieved the desired dry cake solids content but also kept polymer consumption to a minimum. Esmil’s MDQ dewatering technology empowers operators to optimize polymer dosing during setup.  Operators can control the polymer dosing process. They can visually monitor the flocculation tank and adjust polymer dosing in real time. The operator interface terminal (OIT)T allows for precise adjustments to achieve optimal flocculation. Operators can fine-tune the polymer dose until the perfect flocculation point is reached, ensuring maximum efficiency.

The Outstanding Result:

Esmil’s solution not only met but exceeded the customer’s expectations:

  • Achieving High Cake Solids: The MDQ-202CD system successfully increased the dry cake solids to above 20%, dramatically reducing haul-out expenses.
  • Cost Efficiency: Minimizing polymer consumption was achieved without compromising performance, ensuring cost savings and environmental responsibility.
  • Customer Satisfaction: The customer was completely satisfied with our solution, which was installed in March 2023.

Dehydrator MDQ

Case Study: Reconstruction and modernization of the mechanical treatment system at the wastewater treatment plant (Ostrów-Mazowiecka, Poland)

PROJECT: Reconstruction and modernization of the mechanical treatment system at the wastewater treatment plant located on Olszynowa Str. 16 in Ostrów Mazowiecka
CUSTOMER: Public utility company in Ostrów Mazowiecka Sp. z o.o.
SITE: Wastewater treatment facilities on Olszynowa Str. 16
COMMISSIONING: February – March 2021

Project Objectives

The objective of the project was to update and reconstruct the system of removing and collecting waste extracted from wastewater at the wastewater treatment plant in Ostrów Mazowiecka.

According to the modernization plan, the following equipment was delivered, installed and commissioned in February 2021:

  • Esmil RSK0815 step screen with 3 mm gaps
  • SGSM 0.9×2.6 (1.2) penstocks – 2 pcs.
  • Screenings compactor

Until recently, the wastewater treatment plant had been experiencing difficulties with overflowing the channel with wastewater, so it was decided to widen the channel and install a wider screen with a higher capacity.

Project Implementation

The equipment for the project was manufactured at the Esmil plant. The existing inlet channel was enlarged to properly position the screen according to the project requirements. After the completion of the construction work, the Esmil professionals proceeded to the installation and commissioning of the unit. The screen was commissioned in March 2021.


Thanks to the use of the Esmil RSK0815 step screen, the problem of overflowing the channel with wastewater was completely eliminated. The screen selected and supplied by Esmil not only keeps the mechanical treatment facility clean, but also, thanks to its reliable operation, protects the equipment on the further stages of the wastewater treatment process.

Case Study: The Practice of operating the Esmil Catenary Screen at Wastewater Treatment Plants (Budapest, Hungary)

It is no secret that the industry market leader is the most prestigious customer for any supplier of specialized equipment in any given country. In Hungary such customer is certainly the Budapest Waterworks, FCSM Zrt., who provides wastewater treatment in Budapest. Moreover, we feel especially proud of those projects implemented in this city as they received positive professional assessment from the specialists of FCSM Zrt.

One of such projects is the project of manufacturing and installation of a unique Esmil catenary screen for rough wastewater treatment at Angyalföld pumping station that became a substitute to an older coarse screen. In the channel, 6 mtr deep and 3 mtr wide, with the existing transporting conveyor for the wastes from the screen, a new screen had to be installed as soon as possible. Our designers had to focus on the installation and commissioning procedure of the finished product, which was to be delivered from the Esmil plant in Poland.

We can rightfully consider this project as a special operation – due to its non-standard dimensions (3.2 mtr wide, 9 mtr long, weight 2,890 kg), the screen required the use of an escort vehicle; its installation into the channel required high-precision work by the Hungarian team of crane operators and installers. Under the guidance of an Esmil commissioning expert, this operation was performed with surgical precision. Almost 3 hours after the channel had been closed, a penstock was reopened, and the KR 2853 catenary screen was put into operation. The flow rate supplied for this screen ranges from average values of 5-6 thous. m3/hour to 12 thous. m3/hour.

The screen was put into operation in the middle of June of 2020 and during the past six months the operation has clearly demonstrated its efficiency and reliability. The article, published by Waterworks in a professional publication in October 2020, notes the following:

“The Esmil screen, installed in the summer, passed a successful initial inspection. The rakes, located at a distance of about 1 meter from each other, prevent the screen filtering mesh from clogging. Collected wastes remain on the screen filtering mesh for a much shorter period of time compared to the previous one. Consequently, the period of time, when wastes on the filtering mesh can be pressed through by water, is much shorter. Another advantage that could be observed is that the wastes is collected from a screen not with a help of a steel cord, but with a chain made of the same material as the screen itself. This eliminates the possibility of rupture of the steel cord and further interruption in screen operation due to the need of steel cord replacement”.

The article also states that the high efficiency of sewage treatment from all kinds of fibrous and rag materials ensures the stable operation of pumping equipment, which is the most important economic factor. The experts of the Esmil company, together with the employees of the Budapest Waterworks, continue to constantly monitor the operation of the installed catenary screen to control the effectiveness of the applied solutions and their further improvement.

CASE STUDY: Catenary Screen (Olecko, Poland)

Installation of a Catenary Screen and a Screenings’ Wash Press at the Sewage Pumping Station (Olecko, Poland)

PROJECT Modernization of the sewage pumping station in Olecko
INVESTOR Przedsiębiorstwo Wodociągów i Kanalizacji Sp. z o. o. in Olecko
OBJECT Sewage pumping station at Batory street
STARTING December 2018 – June 2019

Plans and Modernization Goals

According to the modernization plan of the pumping station building located at Batory street in Olecko delivery of equipment was divided into two stages:

  1. December 2018 – delivery and installation of the mechanical catenary screen bar type RKC 0827 with
    6 mm clearance.
  2. June 2019 – delivery and installation of SCP 2020 type screenings wash press with Q = 2 m3/h capacity along with the necessary supporting structure.

The purpose of the modernization of the main pumping station was to increase the efficiency of
removing solid parts from inflowing sewage, as well as to reduce the amount of generated screenings
and their hydration.

State from before the Modernization

City’s sewage is directed to the pumping station’s main collecting chamber, and then goes to the grate, which is mounted in a channel with dimensions Bk = 950 mm, Hk = 2000 mm. Before the project, problems related to the presence of the wet wipes occurred, which caused diffi culties in normal gate operation and its blocking. Screenings collected on the grating were transported to the screw conveyor, through which they were transported to the collecting container. The shiſt operator then had to transport the container outside of the building and load it onto the removal vehicle. The main problems associated with the operation of the old devices were:

  • large costs related to the handling and cleaning of the grate from wet wipes and the removal of screenings with a high water content;
  • problems related with stopping the grate too oſten;
  • pump failure and operational problems at further stages of purifi cation that were caused by insufficient efficiency of solid impurities removal.


Aſter analyzing the situation at the pumping station, specialists from Esmil Industrial Group have decided to install a grid prototype to check the efficiency increment comparing to the old device. The RKC 0827 catenary screen bar has been installed at the pumping station, the very first to be produced at our plant. Aſter three months of operation, the management of the plant has decided to buy back the installed device and order SCP 2020 screenings wash press.

As a result of installation of the new equipment, the following results were obtained:

  • Thanks to the use of an innovative chain mechanism that allows efficient collection and extract of a various types of wastes and wet tissues from sewage, the number of failures associated with grid jams has been reduced;
  • The number of removed screenings has doubled due to the use of a grid with a clearance of s = 6 mm within the strainer;
  • The weight of removed screenings has been reduced over three times, thanks to the pressing and rinsing them on the SCP wash press;
  • The time necessary to operate the equipment has decreased by over 95% due to the use of a full automatic mechanical treatment line.

In addition, the following upsides related to equipment replacement should be noted:

  • A significant decrease in the number of failures and repairs at further stages of wastewater and sludge treatment;
  • Total elimination of the need to work in a manual mode when removing screenings from grates.


The modernization of the mechanical sewage treatment system at the pumping station allowed the organization of an effective treatment system for large and medium solid wastes, using a special construction of the grid chain. Screenings, removed from the sewage, are washed to reduce their organic content and pressed on a wash press to reduce their volume and weight.

The installed mechanical cleaning line works fully automatically and does not require constant presence of a personnel. The work of the mechanical wastewater treatment complex has fully met the requirements and ensured stable and trouble-free operation at subsequent stages of treatment.

CASE STUDY: Mechanical treatment (Augustow, Poland)

Project brief

PROJECT – Modernization of the mechanical wastewater treatment facility

CLIENT – Wodociągi i Kanalizacje Miejskie Spółka z o. o. w Augustowie

OBJECT – Augustów WWTP LOCATION Augustów, Poland

COMMISSIONING – January 2017.

The Municipal Wastewater Treatment Plant is situated in the southern part of Augustów. Its capacity is 10 000 m3/d.

In 2016 Esmil Company was chosen to implement investment project for the modernization of the main sewage pumping station which located at the Augustów WWTP. Within the project, the following equipment for mechanical wastewater treatment facility was produced, installed and commissioned:

  1. Rake bar screen RKE;
  2. Screw compacting press SCP;
  3. Slide gates of ZSg type;
  4. Facility control system.

The aim of the pumping station modernization was to increase the efficiency of mechanical impurities removal and waste thickening with full automation of the process.

Initial state:

In accordance with initial project, wastewater was fed via two collectors into the pumping station, where it was mechanically treated on the screens with 25 mm mesh.

Screen cloth cleaning was carried out manually by the personnel as it became clogged. The removed waste was fed into the container for its further lifting by means of lifting device to a zero mark (ground surface) into a receiving tank.

The main problems which were occurring during operation of the old equipment are following:

  • The need of constant monitoring of the screen cloth to prevent pump station flooding and emergencies;
  • High cost of the screen cloth cleaning and further waste transportation into receiving tank;
  • Pumping equipment and further stages emergencies occurring due to insufficient removal of mechanical impurities.

Esmil rake bar screen augustow poland

Project implementation:

One of the key complication during the project implementation was installation of equipment in existed pumping station among which:

The building was not designed for installation of equipment with length of more than 2,5 m, thus there was a requirement to produce rake screen with 6 m length from separate parts with length of 2 m max. Every part was mounted on supporting structure which were brought together inside the pumping station for further parts assembling inside the building.


The modernization project allowed to achieve the following results:

  1. After the new rake screens installation with 5 mm mesh, the amount of removed waste was increased by 2 times.
  2. Due to the partial waste dewatering with screw compacting press SCP, its overall mass has decreased more than 3 times.
  3. The necessary time for equipment maintenance reduced more than by 95 % due to its replacement on the new one which operates in fully automatic mode.

It should be also noted the additional advantages achieved by mechanical wastewater treatment equipment replacement:

  • Considerable decreasing of emergencies and scheduled repairs on the next stages of wastewater treatment technological process.
  • Full elimination of the need for manual labor which were necessary for waste removal earlier. It has significantly improved not only the sanitary condition at the pumping station, but also the labor conditions of the personnel.

The quantity and mass data of the waste removal from the screens in period from 2015 to 2017 is given below in figures. The pumping station modernization was carried out in the fourth quarter of the 2016 and in January 2017, the new mechanical treatment facility was launched; the data from that year indicates significant treatment parameters improvement.

Reliable screen and screw press design provide the treatment facility with a possibility of round-the-clock and trouble-free operation of equipment in automatic mode. Daily maintenance and inspection requires no more than 15 min.

Esmil rake bar screen augustow poland

The amount and mass of wastes removed from the screen in the period from 2015 to 2017

Esmil rake bar screen augustow poland

Time for equipment maintenance in minutes per day


The mechanical treatment facility modernization at the sewage pumping station allowed to organize efficient wastewater treatment from large and average impurities. Removed wastes are rinsed for organic part reduction and are thickened on the screw press for its volume and weigh reduction. Installed mechanical treatment facilities operate in fully automatic mode and do not require constant personnel presence. The mechanical treatment process improvement allowed to solve all of the set challenges and assured stable and uninterrupted wastewater treatment process operation.

Reference of Wastewater Treatment Plant, Mezdra, Bulgaria

Industrial Parts Ltd., with address South Industrial Zone, P.O. 24, 6100, Kazanlak, Bulgaria, issued this Reference to Esmil Industrial Group for successful and professional cooperation with this company.

In March 2015 at the Wastewater treatment plant in Mezdra (Bulgaria) Esmil Industrial Group delivered and commissioned the following equipment:

  • Rake type bar screen RKE with double level sensor in the channel – 1 pcs
  • Combined mechanical treatment module M-Comby (600 m3/h) – 1 pcs
  • Sludge scraper for secondary sedimentation tank – 2 pcs
  • Central driven picket type stripper – 1 pcs
  • Slide gates (manual) – 5 pcs • Slide gates (with electric drive) – 2 pcs
  • Mechanical sludge dewatering belt filter-press – 2 pcs
  • Dewatering sludge screw conveyer KVE – 1 pcs

Since the launch of this complex all kind of equipment works stably providing a high degree of wastewater treatment. With insure qualitatively affected on the operation of wastewater treatment plant in general.

Installation of the mechanized screen allowed to increase the efficiency of the deterrence of waste and their extraction from wastewater.

The complex shows high reliability and minimum maintenance costs.

This equipment is well designed and convenient to operate. Also on the stage of mechanical sludge dewatering we used two belt filter press PL-06C with capacity 6 m3/h. For all operation period equipment under trademark Esmil showed effective and reliable work, high corrosion resistance, low energy consumption.

Esmil Group

Esmil Group stands as a premier global manufacturer, crafting cutting-edge equipment for wastewater treatment and sludge dewatering. Additionally, we specialize in delivering advanced membrane systems tailored to various industries.

EU Flag Esmil Group

Equipment for Wastewater Treatment & Sludge Dewatering.

EU Flag Esmil USA

Equipment for Sludge Dewatering in the USA.

EU Flag Esmil Process Systems

Membrane Systems.